Auto probe (AP) is an electrical function test machine, which is used to load signals to a display screen to detect defects on the display screen. It is mainly used in flat display panel manufacturing industry such as a liquid crystal display panel, a plasma display panel, an organic electroluminescence display panel and so on. The probe unit (PU) is an electrical function test unit, which is a core functional component of AP device. It is usually fixed on a workbench of the electrical function test machine by threaded connection.
However, when performing electrical function tests on different models of display screens, tests are performed by loading specific test signals by replacing the different models of electrical function test units through replacement operations. Frequent replacement of the electrical function test units will cause the threaded hole of the workbench to be damaged (e.g. thread slipping), thus causing the PU to become loose and affecting the normal operation of the device. There are two existing solutions: one is to replace the workbench, but the workbench is large in volume and high in replacement cost; the other is to use special tools to directly trim or rebuild the thread in the threaded hole. However, because of the small aperture of the threaded hole in the workbench, using special tools to trim or rebuild the thread in the threaded hole will cause problems such as long time consuming and low success rate.